Fibrous composition of matter

ABSTRACT

An ignifuge or fire resistant intimate blend of fibres in the form of a composite yarn, a woven fabric made of such composite yarns, a non-woven fabric and textile articles obtained therefrom. The fibres are selected among glass fibres or ceramic fibres surrounded by at least two different kinds of fibres selected among synthetic and/or natural fibres. One of such two fibres has a melting point different from the other of the two fibres and both of the two fibres have melting points lower than the melting point of the glass or ceramic fibre wool and chlorovinyl fibres are among the preferred fibres surrounding the glass fibres. During the melting of the fibres surrounding the glass fibre, at least a partial disintegration thereof takes place and a carbonous deposit is formed on the glass fibres protecting them from heat and increasing heat resistant properties thereof.

United State-s Patent [1 1 Chiarotto [4 1 Oct. 21, 1975 FIBROUSCOMPOSITION OF MATTER [76] Inventor: Nereo Chiarotto, Via Bussola 7,

[30] Foreign Application Priority Data Mar. 17, 1970 Italy 22050/70 July3, 1970 Italy 26982/70 Nov. 12, 1970 Italy 31683/70 [52] US. Cl. 57/144;57/140 BY; 57/140 G; 423/477 [51] Int. Cl. D02g 3/36; D02g 3/44 [58]Field of Search 161/170, 175, 176, 192, 161/150; 57/140 BY, 140 G, 144;423/447 [56] References Cited UNITED STATES PATENTS 3,297,405 1/ 1967Sperk et al 423/447 3,527,564 9/1970 Moore et a1. 423/447 3,572,3973/1971 Austin 57/140 BY X 3,617,220 11/1971 Moore et a1. 423/4473,716,332 2/1973 Leeds 423/447 Primary Examiner-John W. HuckertAssistant Examiner-Charles Gorenstein Attorney, Agent, or FirmGuidoModiano; Albert Josif [57] ABSTRACT An ignifuge or fire resistantintimate blend of fibres in the form of a composite yarn, a woven fabricmade of such composite yarns, a non-woven fabric and textile articlesobtained therefrom, The fibres are selected among glass fibres orceramic fibres surrounded by at least two different kinds of fibresselected among synthetic and/or natural fibresfOne of such two fibreshas a melting point different from the other of the two fibres and bothof the two fibres have melting points lower than the melting point ofthe glass or ceramic fibre wool and chlorovinyl fibres are among thepreferred fibres surrounding the glass fibres. During the melting of thefibres surrounding the glass fibre, at least a partial disintegrationthereof takes place and a carbonous deposit is formed on the glassfibres protecting them from heat and increasing heat resistantproperties thereof.

8 Claims, No Drawings 1 FIBROUS COMPOSITION OF MATTER BACKGROUND OF THEINVENTION The present invention relates to a fibrous composition ofmatter, in particular for obtaining products with improved ignifugecharacteristics. More particularly, the present invention relates tocomposite yarns having improved ignifuge characteristics, to fabricsobtained by said yarns and to non-woven fabrics having improved ignifugecharacteristics, obtained from said fibrous composition of matter.

By the term ignifuge is generally meant a property of a fabric whichdoes not permit the spreading or propagation of a flame (i.e. fireresistant). It is known that a fabric can be ignifuge because his formedfrom ignifuge fibres or because it is formed from fibres which, afterthe fabric has been made, are processed, such as by impregnationtreatment with suitable substances which confer said ignifuge propertyto the fabric.

The problem facing the experts in the art during the conceiving of afabric having ignifuge properties, above all of a fabric to be employedfor obtaining textile goods which is applicable to the clothing fieldand/or furnishing field, is represented by the necessity of conferringthe fabric in the course of its manufacture, both with ignifugecharacteristics, and with all those properties conventionally requiredfrom a fabric to be employed in the clothing field and/or furnishingfield. It is known that, for some time, persons skilled in the art havebeen constantly in search of fibres that can satisfy and solve theproblem or have been in search of sub stances for impregnating fabrics,which substances, while conferring to the fabrics the desiredfire-resistant properties, would not diminish their other properties orcharacteristics. Thanks to said continual research, there are currentlyavailable ignifuge fabrics which appear satisfactory up to maximumtemperature values in the order of 400-500 C. On achieving or exceedinga temperature of the above order, in ignifuge fabrics currentlyavailable, there occurs a disadvantage caused by the fact that thefabric, both when obtained from ignifuge fibres or when impregnated withignifuge substances, becomes easily perforated or is heatconductive as,for example, in the case of glass fibres.

In fact in fire accidents it is not only important to prevent thes'preading of fire over the clothes, but also to prevent eccessive heatto reach the body of the user.

SUMMARY OF THE INVENTION The main object of the present invention is toproduce a flameproof, heat-insulating composition of matter which can beprocessed into yarns, textiles, and non-woven fabrics suitable forapplication in the garment and furnishing field as well as forindustrial applications, and whose flameproof properties are such as notonly to prevent the spreading of the flame, but also to resistperforation by a flame at temperatures higher than 400-500 C which isthe maximum temperature at which flameproof fabrics at presentcommerciallyavailable can resist. r

It is a further object of this invention to produce a fibrouscomposition of matter with properties of the above-mentioned type thatcan easily be formed from materials which are normally commerciallyavailable, employing production processes of a known type so as to beadvantageous also from the strictly economic point of view. r

and of at least two fibres selected from the group consisting ofsynthetic fibres, natural fibres and blends thereof the synthetic andnatural fibres having a melting point below the melting point of saidglass fibres and which, when melting, form on said glass fibres asubstantially carbonous residue.

The term melting point as used in this specification should be intendedin the sense of a melting process which involves at least a partialdisintegration of the molecular structure of the fibre and in which theboundaries between the pure melting process and the pure disintegrationmight not be exactly defined.

In one of its aspects, the present invention relates to a compositeyarn, comprising a glass-fibre core and a coating for said core formedfrom at least two fibres selected from the group consisting of syntheticfibres, natural fibres and blends thereof having melting points whichdiffer from each other and are below the melting point of said glassfibres and which, when melting, form on said, core a substantiallycarbonous residue, said melting involving atleast a partialdecomposition.

By the term glass fibres, as used in this specification and in theaccompanying claims, are meant common glass fibres, beta glass fibres,ceramic fibres and the like fibres. Beta glass fibres appear to be ofpar-- ticular advantagefor the applications of this invention. Betafibres are manufactured by Owens-Corning Fiberglas Corporation ofU.S.A'., but under the term Beta glass fibres as used in thisspecification glas fibres having singularly a diameterof less than 5microns should be intended. Synthetic and/or natural fibres havingdisintegrative melting points lower than that of said glass fibres,useful in the present invention, comprise, woollen fibres, artificialproteic fibres, naturalsilk fibres, chlorovinyl fibres, modacrylicfibres, acrylonitrile fibres, polyester fibres, polyamide fibres,cellulose fibres, preventively treated with fire-resistant substancesand their blends.

Particularly advantageous, in applications of this invention are woolenfibres and chlorovinyl fibres, in combination with said glass fibres andin particular with beta glass fibres.

Further characteristics and advantages of the invention will betterappear from the description of examples of the fibrous composition ofmatter, of yarns and nonwoven fabrics obtained therefrom, which aregiven hereinafter as indicative and not limitative examples.

DESCRIPTION 'OF THE PREFERRED EMBODIMENTS EXAMPLE I -Milan, Italy.Saidpolychlorovinyl fibre melts, without flame, at a temperature ofabout 250 C while wool notoriously bumsslowly, melting at a temperatureof over 300 C. Beta glass,,which forms the thread-core of the compositeyarn according to the present invention, ha

5 a meltingpoint of about,1,000 C.

The weight proportions of the components of the yam'were as follows: 100parts by weight of Td 100 Beta fibre glass, 60 parts by weight of 66wool and 40 parts by weight of polychlorovinyl fibre Leavin of 3deniers. First a roving of wool and Leavin fibres was madewith theindicated proportions in conventional manner and the roving and thefiber glass thread were joined by the conventional core'spun technique.A composite ya'rn has been obtained in which a core of fibre glass wascompletely surrounded by fibres of wool and Leavin forming a coating.

The composite yarn thus obtained was exposed to a Bunsen flame of about800 C. First the melting of the Leavin fibre was observed, which formeda deposite on the other fibres retarding the heat action thereon.Subsequently the wool fibres begun to melt and decompose. I I I It wasobserved thatthe melting residue of Leavin fibres and the meltingresidue of wool fibres mixed and formed a carbonous residue which made aprotective and insulating deposite on the glass fibres. The yarn showeda surprising heat and fire resistance. It is believed that thesesurprising fire and heat resisting properties are aided by the followingmechanism.

Initially, the decomposition of the polychlorovinyl fibre takes placewith the development of acidic gas and a deposit of said fibre on otherfibres with which his intimately mixed. At a given point, the woolfibres which have an inflamability point of about 600 C begin tomeltwith the development of basic gas. The two gases developing from themelting of the polychlorovinyl and wool fibres, partly neutralize eachother, thus preventing the wool from burning, due to lack of oxygen; theamalgam formed from the chlorovinyl residues and of the carbon residuesoriginating from the wool are depositated on the beta glass fibre (thecore of the composite yarn). This glass fibre is thermically protectedby such residues deposited on it, "resisting up to over 900 C beforeinitiating the melting process.

The composite yarn according to the invention was woven, forming textilegoods having, in addition to the above mentioned surprising ignifugecharacteristics, all those properties normally required for clothing andfurnishings. The tests carried out, showed that, when subjected to theaction of fire the heat insulating properties of the fabric remarkablyincreased.

EXAMPLE 2 EXAMPLE 3 A- composite yam was obtained according toindications of example 1, substituting the wool with natural silk. Inthis case, when subjected to a flame, the yarn resisted up to atemperature in the order of 700 C.

EXAMPLE 4 v Following the indications of example I, a composite yarn wasobtained by employing, as the core of said:

yam, beta glass fibres, and an intimate bend of modacrylic fibre'andwool fibre as a coating. This composite yarn, when subjected to theaction of the flame, resisted up to temperatures in the order of 700-750C.

v EXAMPLE 5 v The procedure of Example 4 was repeated, substituting thewool fibres with artificial proteic fibres and/or with silk .fibres. Thecomposite yarn obtained had fireresistant characteristics comparablewith those of the yarn of Example 4. v

EXAMPLE 6 I The procedure of obtaining a yarn according to Example 4 wasfollowed; wherein however the coating of the beta glass fibre wasobtained by first forming a thread from the rovings of acrylonitrilicand polyester fibres and then jointing together suchthread with thethread of glass fibre by a conventional end-to-end technique. Thecomposite yarns obtained according to this example, subjected to theaction of the flame, resisted up to a temperature in'the order of550-600 C.

k EXAMPLE 7 The procedure for obtaining a composite yarn according toexample'l was'followed, substituting the chlorovinyl fibre withpolyester. When subjected to the flame, the composite yarn resistedtemperatures'in the order of 550600 C.

' EXAMPLE 8 The procedure as described in Example I was followed withthe exception that the polychlorovinyl fibre was substituted by 66polyamide fibre, while the wool was substituted each time by otherartificial proteic fibres or by natural silk. In each case compositeyarns were always obtained which resisted high temperatures, comparablewith those against which the yarn obtained by Example 1 resisted.

EXAMPLE 9-9A The procedure according-to that described in examples 1-8was followed, with the exception that a beta glass fibre wassubstituted, the first time, with a common glass thread, and the secondtime with a ceramic thread, thus obtaining two composite yarns whichresisted a temperature in the order of 600-650 C before melting, whichmeans that they had altogether surprising ignifuge characteristicscompared with the fireresistant characteristics of yarns up to nowknown.

The yarns obtained according to the previous examples, were woven andshaped into textile goods having, in addition to the above-mentionedsurprising ignifuge and insulating characteristics, all those propertiesnormally required from fabrics which are applicable to the fields ofclothing industry, furnishings and other known industrial applications.

It has been found that the same fibres which form the composite yarninexamples 1-9-9A, could advantageously be usedin obtaining fabrics ofthe so-called non-woven type or felted fabrics, havingmost markedignifuge characteristics and practically comparable with those of thecomposite yarn as in the above examples, and of fabrics obtained fromsaid composite yarn.

The non-woven fabric of theabove-mentioned type issuitable for numerousapplications among which the most remarkable ones are the obtaining oflinings or stuffirigsQwall-tO-wall carpets of the moquette type,

so-called pressed articles, on prior impregnation of the non-wovenfabric, with appropriate bending or adhesive agents as additives; thsesarticles had the same surprising and highly desired ignifuge andincreased insulating characteristics under the action of fire.

These non-woven fabrics can be manufactured by intimately blending afirst fibre selected from the group comprising beta glass fibres, commonglass fibres, ceramic fibres and silicious fibres, with at least twoother fibres which are selected from natural and/or synthetic fibres,these natural and/or synthetic fibres having different melting points,and below the melting point of said first fibre, and forming, onmelting, a substantially carbonaceous residue on said first fibre.

Advantageously, said second fibres are selected from wool fibres,artificial proteic fibres, natural silk fibres, chlorovinyl fibres,modacrylic fibres, acrylonitrilic fibres, polyester fibres, polyamidefibres, and their blends.

The following are some examples of non-woven fabrics obtained withfibres of the above-mentioned type.

EXAMPLE 10 kg. of glass tuft or flock and 10 kg. of wool tuft or flockand 10 kg. of polychlorovinyl tuft were thoroughly mixed, and anon-woven fabric of the felted type was obtained therefrom byconventional techniques. Repeated and strictly controlled tests, showedvery high ignifuge properties, currently unavailable in the knownnon-woven fabrics, and even higher than the ignifuge properties of thesingle fibres composing the fabric thus obtained. This was explained bya cooperative ignifuge action of surface and near to surface layers ofthe fabric.

With the non-woven fabric of this example, paddings or stuffings ingeneral were easily obtained as for instance paddings for furnishings,motor-car seats, to the obtaining of covering elements such as forinstance wall-to-wa1l carpets and the like, which all had the samedesired fire-resistant characteristics.

On prior impregnation with appropriate adhesive additives, as forexample chlorovinyl resins and the like resins, and subsequent moulding,with the non-woven fabric of Example 1, shaped pressed articles, havingample and different applications and the desired ignifugecharacteristics, were obtained.

EXAMPLE 1 l A non-woven felted-type fabric was obtained in aconventional manner by intimately mixing 10 kg. of ceramic fibre, 10 kg.of modacrylic fibre and 10 kg. of wool or other artificial proteicfibres or silk. In all cases, the non-woven fabric thus obtained whensubjected to the effect of a flame, resisted very high temperatures inthe order of 700C before the melting process of the internal layers ofthe fabric started. Similarly, as already mentioned in Example 10, thisnonwoven fabric was used to obtain articles such as, for example,paddings or stuffings, articles for covering and the like, all havinghigh ignifuge characteristics.

In other embodiments of the non-woven fabric of this invention,different combinations of glass fibres, ceramic fibres, beta glassfibres in an intimate blend with at least two other fibres of which onewas selected from the group of woollen fibres, artificial proteicfibres, natural silk fibres and the other one was selected from thegroup of chlorovinyl, modacrylic, acrylonitrilic, polyester, polyamideand the like fibres or their blends, were used. All the non-wovenfabrics obtained from these combinations had surprising ignifugecharacteristics and were easily processable for obtaining textile goods,such as paddings in general, covering articles, ropes and the like. Onprior impregnation with adhesive substances of the synthetic resinstype, compatible with the employed synthetic fibres and with simplemoulding operations by pressing, it was possible to obtain shaped orpressed articles in different forms and of different even considerabledimensions, all having the desired ignifuge characteristics.

In a particular application of the non-woven fabric according to theinvention, a fabric formed substantially of three adjacent layers wasobtained in a single piece. Each layer was formed of three types offibres, selected from the above mentioned groups, each layer having,with respect to the other adjacent layers, either the same quantitativecombination of the three fibre types of different combinations, with onefibre type prevailing with respect to the remaining two.

Yarns obtained as above described but inwhich instead of Leavin fibresthe following vinyl fibres were used.

Fibravyl manufactured by the French Company Soc.

Rhovyl Clevyl T manufactured by the French Company Soc.

Rhovyl Rhovyl manufactured by the French Company Soc.

Rhovyl Thermovyl manufactured by the French Company Soc. Rhovyl Vinyonmanufactured by the USA. Union Carbide Corp.

showed similar surprising ignifuge characteristics.

I claim:

1. A composite yarn which exhibits fire resistant properties due tothermal decomposition, said yarn comprising a glass-fiber core, acarbonizable coating for said core consisting of a blend of a naturalanimal fiber witha synthetic fiber, said coating exhibiting thermaldecomposition, upon being subjected to high temperatures, and forming asubstantially carbonaceous residue rendering the yarn fire resistant.

2. The composite yarn of claim 1, wherein said glass fiber is selectedfrom the group consisting of beta glass fibers, common glass fibers,ceramic fibers and mixtures thereof.

3. The composite yarn of claim 1, wherein said natural fiber is selectedfrom the group consisting of wool fibers, silk fibers, artificialproteic fibers and mixtures thereof.

4. The composite yarn of claim 1, wherein said synthetic fiber isselected from the group consisting of polyvinylchloride fibers,polyamide fibers, modacrylic fibers, polyester fibers,polyacrylonitrilic fibers and mixtures thereof.

5. The composite yarn of claim 1, wherein said glass fiber core consistsof a filament of beta glass and said coating consists of an intimateblend of polyvinylchloride fibers and wool fibers.

6. The composite yarn of claim 5, wherein said glass filament is wrappedby said polyvinylchloride fibers and wool fibers which form a tube-likecoating for said filament.

7. The composite yarn of claim 5, wherein the weight ratio glassfibersz'polyvinylchloride fibers: wool fibers is approximately :4O:6O.

8. A fabric made of composite yarn of claim 1.

1. A COMPOSITE YARN WHICH EXHIBITS FIRE RESISTANT PROPERTIES DUE TOTHERMAL DECOMPOSITION, SAID YARN COMPRISING A GLASSFIBER CORE, ACARBONIZABLE COATING FOR SAID CORE CONSISTING OF A BLEND OF A NATURALANIMAL FIBER WITH A SYNTHETIC FIBER, SAID COATING EXHIBITING THERMALDECOMPOSITION, UPON BEING SUBJECTED TO HIGH TEMPERATURES, AND FORMING ASUBSTANTIALLY CARBONACEOUS RESIDUE RENDERING THE YARN FIRE RESISTANT. 2.The composite yarn of claim 1, wherein said glass fiber is selected fromthe group consisting of beta glass fibers, common glass fibers, ceramicfibers and mixtures thereof.
 3. The composite yarn of claim 1, whereinsaid natural fiber is selected from the group consisting of wool fibers,silk fibers, artificial proteic fibers and mixtures thereof.
 4. Thecomposite yarn of claim 1, wherein said synthetic fiber is selected fromthe group consisting of polyvinylchloride fibers, polyamide fibers,modacrylic fibers, polyester fibers, polyacrylonitrilic fibers andmixtures thereof.
 5. The composite yarn of claim 1, wherein said glassfiber core consists of a filament of beta glass and said coatingconsists of an intimate blend of polyvinylchloride fibers and woolfibers.
 6. The composite yarn of claim 5, wherein said glass filament iswrapped by said polyvinylchloride fibers and wool fibers which form atube-like coating for said filament.
 7. The composite yarn of claim 5,wherein the weight ratio glass fibers: polyvinylchloride fibers: woolfibers is approximately 100:40:60.
 8. A fabric made of composite yarn ofclaim 1.